1. Field of the Invention
This invention relates generally to methods of and apparatus for transporting articles, and, more particularly, to methods of and apparatus for transporting and testing electronic devices having indentations in their body portions.
2. Description of the Prior Art
In manufacturing many types of electronic devices large-scale testing is often required to insure product quality. Due to various body configurations and the presence of delicate leads, such testing is sometimes difficult. But since many configurations have become relatively standardized, commercial test handlers are frequently available.
New problems in the testing area have arisen by the introduction of light-emitting diodes (LED's). Often these light-emitting diodes have body configurations which generally have not been previously encountered. An example of this is the light-emitting diode used in some telephone handsets. Such a light-emitting diode is shown in U.S. Pat. No. 3,774,021 issued to B. H. Johnson, and assigned to Bell Telephone Laboratories in an article by Alfred E. Bakanowski published in the Bell Laboratories Record, June 1977, pages 161-62. This particular diode has a cylindrical body portion formed of transparent epoxy which encapsulates a light-emitting semiconductor chip. A pair of fragile flat leads extend from the curved side of the device parallel to one another. An indentation in the body portion creates a "reflecting dimple" to allow for a better scattering of the light from the curved sidewalls of the diode.
Since the leads of the above-described light-emitting diode extend from the curved side of the body portion rather than the flat portion, conventional test handling equipment is generally not suitable for transporting and testing the diode.
Attempts have been made to test the diodes while they are in a rack with the leads hanging downward. However, it was found that it is extremely difficult to bring the leads into proper alignment with the test contacts in this position. Such alignment is necessary to obtain good testing contact for accurate measurements of the electrical parameters and light output of the diode.